SECTION 304

DIVISION 300-- BASE COURSES

SECTION 304 -- AGGREGATE BASE COURSE

Description

1.1 This work shall consist of furnishing and placing base courses on a previously prepared subgrade or course as shown on the plans or as ordered.

1.2 This work shall also include raising the grade of the edge of the roadway shoulders with crushed aggregate as shown on the plans or as ordered to match the grade of the pavement course placed on the shoulders or to provide a base for shoulder pavement.

Materials

2.1 General.

2.1.1 The materials shall consist of hard, durable particles or fragments of stone or gravel. Materials that break up when alternately frozen and thawed or wetted and dried shall not be used for aggregate base course materials. Fine particles shall consist of natural or processed sand. The materials shall be free of harmful amounts of organic material. Unless otherwise specified, the percent wear of base course material shall not exceed 50 percent as determined by AASHTO T 96, Grading A. 2.1.2 Crushed stone shall be processed material obtained from a source that has been stripped of all overburden. The processed material shall consist of clean, durable fragments of ledge rock of uniform quality and reasonably free of thin or elongated pieces. 2.1.3 Materials for glass cullet shall either be separated/recyclables received from a recycling facility permitted (pursuant to RSA 149-M:10) by the Waste Management Division of the Department of Environmental Services and/or materials certified for Direct Re-Use in accordance with Section 318 of the New Hampshire Solid Waste Rules. 2.1.3.1 Glass cullet shall meet the requirements of AASHTO M318. 2.2 Gradation. The required gradation of base course material shall conform to Table 1. 2.3 Sand. The maximum size of any stone or fragment shall not exceed three-fourths of the compacted depth of the layer being placed but in no case larger than 6 in. (150 mm). 2.4 Gravel. The maximum size of stone particles shall not exceed three-fourths of the compacted thickness of the layer being placed but in no case larger than 6 in. (150 mm). 2.5 Crushed gravel. At least 50 percent of the material retained on the 1 in. (25.0 mm) sieve shall have a fractured face. 2.6 Crushed gravel for shoulder leveling. This material shall consist of crushed aggregate for shoulders meeting the gradation requirements of Table 1 and shall then be mixed with at least 25 percent by volume of loam meeting the requirement of 641.2.1.

2.7 Crushed aggregate for shoulders. This material shall meet the gradation requirements of Table 1.

2.8 Gravel for drives. The material shall meet the requirements of gravel as shown in Table 1.

2.9 Crushed gravel for drives. The material shall meet the gradation requirements of either crushed gravel or crushed stone (fine) as shown in Table 1.

2.10 Crushed stone base course (fine gradation). Acceptable sand may be blended as necessary to obtain the proper gradation for the fine aggregate portion.

New Hampshire Department of Transportation Standard Specifications – 2010 3-37 SECTION 304

Table 1 -- Base Course Materials Required Gradation Item No. 304.1 304.2 304.3 304.33 304.4 304.5 304.6

Crushed Crushed Crushed Crushed Crushed Aggregate Item Sand Gravel Stone Stone Stone Gravel For (Fine) (Coarse) (Very Coarse) Shoulders

Sieve Size Percent Passing By Weight

6 in. (150 mm) 100 100 ------100 5 in (125 mm) ------4 in (100 mm) ------3 ½ in. (90 mm) ------100 --- 3 in. (75 mm) ------100 ------85 – 100 60-90 2 ½ in. (63.5 mm) ------2 in. (50 mm) ------95 – 100 --- 100 ------1 ½ in. (37.5 mm) ------100 85 – 100 60 – 90 45-75 1 in (25.0 mm) ------55 – 85 90 – 100 ------¾ in. (19.0 mm) ------45 – 75 40 – 70 35-65 #4 (4.75 mm) 70 – 100 25 – 70 27 – 52 30 – 65 10 – 45 15 – 40 15-40 # 200 (0.075 mm) (In 0 – 12 0 – 12 0 – 12 ------Sand Portion)* # 200 (0.075 mm) (In ------0 – 10 0 – 5 0 – 5 0-5 Total Sample) * Fraction passing the # 4 (4.75 mm) sieve

2.11 Crushed stone base course (coarse gradation). Acceptable sand may be blended as necessary to obtain the proper gradation for the fine aggregate portion.

2.11.1 The substitution of crushed stone meeting the requirements of crushed stone base course (fine gradation) for all or part of this item will be permitted.

Construction Requirements

3.1 General.

3.1.1 Upon approval, base course materials found within the project limits may be used under the specific item in accordance with 104.04.

3.1.2 Gravel or approved substitution for gravel may be substituted for any sand course. Crushed gravel may be substituted for gravel. Substitutions must be made across the entire section and will not be allowed for short or discontinuous segments.

3.1.3 Crushed stone (fine gradation) may be substituted for crushed gravel provided there is a minimum of 1 ft (0.3 m) of free draining material (sand, gravel, crushed stone coarse, or crushed stone very coarse) below the crushed stone. The substitution must be made across the entire section and will not be allowed for short or discontinuous segments.

3.1.3.1 Also, permission may be granted to use reclaimed stabilized base in lieu of crushed gravel or crushed stone (fine gradation) provided the following requirements are met:

New Hampshire Department of Transportation Standard Specifications – 2010 3-38 SECTION 304

(a) The material shall meet the requirements of 306. (b) The approved material shall be applied across the entire cross-section at a constant depth. Short or discontinuous sections as determined by the Engineer will not be allowed. (c) Transitions between reclaimed asphalt and crushed gravel or crushed stone (fine gradation) shall be made using a 50 ft (15 m) taper. (d) Reclaimed asphaltic material shall be placed directly under the proposed pavement.

3.1.3.2 Also, permission may be granted to use reclaimed asphalt pavement blended with granular material meeting the requirements of 304 in lieu of crushed gravel or crushed stone base course (fine gradation) providing that the following requirements are met:

(a) The material shall meet the gradation requirements of the material being replaced. (b) The approved material shall be applied across the entire cross-section at a constant depth. Short or discontinuous sections as determined by the Engineer will not be allowed. (c) Transitions between reclaimed asphalt and crushed gravel or crushed stone (fine gradation) shall be made using a 50 ft (15 m) taper. (d) This material shall be placed directly under the proposed pavement.

3.1.3.3 Crushed stone (coarse or very coarse) may be substituted for gravel provided that all crushed gravel above the crushed stone is replaced with a combination of crushed stone coarse and fine with the top layer consisting of a minimum of six in. of crushed stone fine. The substitution must be made across the entire section and will not be allowed for short or discontinuous segments.

3.1.4 Crushed aggregate base course materials shall be produced and placed in their final location with as little segregation as possible.

3.1.5 Excess reclaimed stabilized base material substantially meeting the requirements of 2.7 may be substituted for the crushed aggregate for shoulders in 2.6. Reclaimed stabilized base material shall be mixed with loam as specified in 2.6.

3.1.5.1 Reclaimed stabilized base material shall not be substituted for crushed aggregate for shoulders in areas contiguous to residences and other existing landscaped areas where the growth of grass is desired.

3.2 Aggregate Crushing Plant.

3.2.1 The equipment for producing crushed gravel shall be of adequate size and with sufficient adjustments to produce the required materials without unnecessary waste. The plant shall be capable of removing excess fines.

3.2.2 The equipment for producing crushed stone shall consist of sufficient units with sufficient adjustments to produce the required material. The plant shall be capable of removing undesirable material and excess fines. In order to meet the required gradation, the Contractor may produce acceptable material in one operation or combine coarse and fine piles through a proportioning hopper to create a combined stockpile.

3.2.3 Glass Cullet Crushing Plant

3.2.3.1 The glass cullet crushing plant shall be capable of producing a product meeting the gradation requirements of AASHTO M 318.

3.2.3.2 Glass cullet shall be thoroughly mixed with other base course materials to produce a homogeneous blend prior to being placed on the roadway. In-place field blending of glass cullet with other base course materials will not be permitted, unless otherwise permitted.

3.3 Stockpile Construction.

3.3.1 All crushed aggregate base course materials shall be stockpiled. The Contractor shall give the Engineer advance notification of when the manufacturing and stockpiling are to begin.

New Hampshire Department of Transportation Standard Specifications – 2010 3-39 SECTION 304

3.3.2 A stockpile of acceptable material, as described in 3.5, equal to at least 20 percent of the bid quantity or 5,000 yd3 (4000 m3), whichever is less, shall be constructed before the hauling and placing phase of the work begins. The stockpile shall be maintained until approximately 80 percent of the quantity has been placed.

3.3.3 Stockpiles shall be constructed in layers that minimize segregation. The desired optimum thickness of layers is 6 ft (1.8 m) and in no instance shall the layer be more than 10 ft. (3 m). Each layer shall be completed before the next layer is started. Construction of stockpiles by direct use of a fixed conveyor belt system or by dumping over a bank will not be permitted.

3.4 Placing.

3.4.1 The subgrade or preceding course shall be shaped to the specified crown and grade and maintained in a smooth condition free of holes and ruts. If the hauling equipment causes ruts in the subgrade or previously placed base course, the equipment shall be operated only on the course being placed, behind the spreading equipment.

3.4.2 Care shall be taken to avoid segregation during placement. Base course material shall be dumped on the course being placed and spread at once onto the previously placed layer. If spreading equipment is not available, dumping will not be permitted. Any segregation that occurs shall be remedied or the materials removed and replaced at no additional cost to the Department.

3.4.3 The Contractor's method of operation shall be such that oversized stones will not be delivered to the project.

3.4.4 When the base course is to be surface-treated and no pavement is to be placed upon it, stones having any dimension greater than 3 in. (75 mm) shall be removed from the upper 4 in. (100 mm) of the top layer.

3.4.5 Prior to fine grading, hard spots in the surface of the top layer shall be eliminated by scarifying the top 4 in. (100 mm).

3.4.6 Crushed gravel for shoulder leveling shall be spread uniformly along the area adjoining the edge of the pavement. The material shall be spread along both sides and under guardrail where there is no curb.

3.4.6.1 Reclaimed stabilized base material utilized in shoulders greater than 1½”, in any direction, shall not be exposed after placement.

3.4.7 To prevent segregation of crushed aggregate during spreading and to assist in obtaining the required density of the mixture, water may be added to the crushed aggregate prior to performing the grading operations. The course shall be maintained in the moist condition during grading operations.

3.4.8 Crushed aggregate shall be hauled from an approved stockpile. Material obtained directly from a conveyor shall not be placed on the roadway without first stockpiling.

3.4.9 The base course material shall be spread in the amount necessary for proper consolidation and shall be shaped true to grade and cross-section by means of power graders or other approved equipment.

3.4.10 Surface voids in crushed stone base course (fine gradation) shall be eliminated by the addition of filler material to just fill the voids. Any surplus filler material shall be removed. The finished surface shall be uniform, true to grade, and free from segregation. The Contractor shall furnish and place filler material to correct any visible segregation prior to paving. The filler material shall be spread, scarified, if required, into the course, and recompacted to the required density. Filler material shall meet the gradation requirements of sand. The final gradation of crushed stone base course (fine gradation) shall meet the requirements of Table 1.

3.5 Testing For Gradation.

3.5.1 Sampling procedure shall conform to AASHTO T 2. Testing procedures shall be in accordance with AASHTO T 27.

New Hampshire Department of Transportation Standard Specifications – 2010 3-40 SECTION 304

3.5.1.1 When reclaimed asphalt pavement is blended with granular material to be used in lieu of crushed gravel or crushed stone base course (fine gradation) the method used to determine the amount of coarse material shall be determined according to NHDOT S-1.

3.5.2 The amount of material finer than the No. 200 (0.075 mm) sieve shall be determined according to AASHTO T 11, which specifies dry sieving after washing.

3.5.2.1 When reclaimed asphalt pavement is blended with granular material to be used in lieu of crushed gravel or crushed stone base course (fine gradation) the method used to determine the amount of material finer than the No. 200 (0.075 mm) sieve shall be determined according to NHDOT S-1.

3.5.3 For a preliminary determination of compliance with the specification for gradation, samples of sand and gravel may be taken from the pit, and samples of crushed gravel and crushed aggregate may be taken from the stockpile or from the final phase of the crushing operation. Materials not meeting the gradation requirements shall not be placed on the roadway

3.5.4 Samples for acceptance testing of the material in place will be taken from each lift. Sampling for acceptance testing will not be done until the material has been graded and compacted.

3.5.5. Previously tested and accepted material contaminated by earthen, organic, or other foreign matter or degraded by hauling equipment to such an extent that the material no longer meets the gradation requirements shall be removed and replaced or otherwise made acceptable at the Contractor's expense.

3.6 Compaction.

3.6.1 Unless shown on the plans or ordered otherwise, the compacted depth of sand courses shall not exceed 12 in. (300 mm). The compacted depth of any layer of gravel, crushed gravel, or crushed stone placed shall not exceed 8 in. (200 mm).

3.6.2 Compaction of base course material shall be done with a method and adequate water to meet the requirements of 3.7. Rolling and shaping shall continue until the required density is attained. 3.6.3 Rolling and shaping patterns shall begin on the lower side and progress to the higher side of the course while lapping the roller passes parallel to the centerline. Rolling and shaping shall continue until each layer conforms to the required grade and cross-section and the surface is smooth and uniform. 3.6.4 Water shall be uniformly applied over the base course materials during compaction in the amount necessary for proper consolidation. 3.6.5 When vibratory equipment is being operated, the amplitude of vibrations, the compaction process shall be adjusted as necessary to avoid causing damage or vibration complaints to adjacent buildings and property. 3.6.6 Except at inaccessible locations, such as near guardrail, material used for shoulder leveling shall be set with a pneumatic-tired roller. 3.7 Density Testing. 3.7.1 The density of sand courses shall be determined by AASHTO T 191 (Sand-Cone Method), AASHTO T 204 (Drive Cylinder Method), or AASHTO T 238 (Nuclear Methods). The density shall not be less than 95 percent of the maximum density determined in accordance with AASHTO T 99 (Standard Proctor Test) or a control strip. (See 3.8.) 3.7.2 The density of gravel and crushed gravel courses shall be determined by AASHTO T 191 (Sand-Cone Method) or AASHTO T 238 (Nuclear Methods). The density of crushed stone base courses shall be determined by AASHTO T 238 (Nuclear Methods). The density shall not be less than 95 percent of the maximum density as determined by AASHTO T 99 (Standard Proctor Test) or a control strip. (See 3.8.) 3.8 Control Strip Procedure. 3.8.1 At the beginning of the compaction operation a control strip of at least 100 linear ft (30 m) in length and spanning the width of the section being placed shall be constructed. The density requirement shall be determined by compacting the control strip at a suitable moisture content until no further increase in density can be measured. The remainder of the course shall be compacted to a density not less than 95 percent of the maximum control strip density, as measured by the nuclear density testing equipment. A new control strip will be required when there is a significant change in the gradation of the

New Hampshire Department of Transportation Standard Specifications – 2010 3-41 SECTION 304 material being placed or a change in compaction equipment. Compaction of the control strip shall be done with approved vibratory rollers or compactors capable of producing a dynamic force of at least 27,000 lb (120 kN). 3.8.2 Crushed gravel for roundabout truck apron curb shall be compacted to a density not less than 98 percent of the maximum control strip density, as measured by the nuclear density testing equipment. 3.9 Winter Construction. 3.9.1 Base course materials shall not be placed on or above frozen material if the depth from the top of the contemplated course to the bottom of the frozen material exceeds 2-1/2 ft (750 mm). 3.9.2 If the density requirements are not attained for any layer before the material freezes, no further material shall be placed on that layer. 3.10 Maintenance of Traffic. Glass cullet base course blends shall be capped with standard specification base course materials before the traveling public is allowed to drive over the material. Method of Measurement 4.1 Roadbed base course materials of sand, gravel, crushed gravel, crushed aggregate for shoulders, crushed stone (fine gradation), and crushed stone (coarse gradation) will not be measured, but shall be the cubic yard (cubic meter) final pay quantity in accordance with 109.11 of compacted material required within the lines shown on the plans. 4.2 Applicable provisions as stated in 106.02 shall apply to base course materials. 4.3 Crushed gravel for shoulder leveling will be measured by the ton (metric ton) in accordance with 109.01. 4.3.1 Reclaimed stabilized base material used for crushed gravel for shoulder leveling shall be measured by the cubic yard using average lengths, widths and depths of the area to be filled or as provided in 4.3 as determined by the Engineer. 4.4 Gravel and crushed gravel for drives will be measured by the cubic yard (cubic meter) of compacted materials placed within the limits shown on the plans. Basis of Payment 5.1 Roadbed base course materials of sand, gravel, crushed gravel, crushed aggregate for shoulders, crushed stone (fine gradation), and crushed stone (coarse gradation) are final pay quantities and will be paid for at the Contract unit price per cubic yard (cubic meter) in accordance with 109.11. 5.1.1 Reclaimed stabilized base authorized for use in lieu of crushed gravel or crushed stone (fine gradation) will be paid for as provided in 5.1 5.2 Filler material used to eliminate voids in crushed stone base course (fine gradation) will be subsidiary. 5.3 The accepted quantity of gravel or crushed gravel for drives will be paid for at the Contract unit price per cubic yard (cubic meter) complete in place. The accepted quantity of crushed gravel for shoulder leveling will be paid for at the Contract unit price per ton (metric ton) delivered and used on the project. Pay items and units: 304.1 Sand (F) Cubic Yard (Cubic Meter) 304.2 Gravel (F) Cubic Yard (Cubic Meter) 304.25 Gravel for Drives Cubic Yard (Cubic Meter) 304.3 Crushed Gravel (F) Cubic Yard (Cubic Meter) 304.32 Crushed Gravel for Shoulder Leveling Ton (Metric Ton) 304.33 Crushed Aggregate for Shoulders (F) Cubic Yard (Cubic Meter) 304.35 Crushed Gravel for Drives Cubic Yard (Cubic Meter) 304.4 Crushed Stone (Fine Gradation) (F) Cubic Yard (Cubic Meter) 304.5 Crushed Stone (Coarse Gradation) (F) Cubic Yard (Cubic Meter) 304.6 Crushed Stone (Very Coarse) Cubic Yard (Cubic Meter)

New Hampshire Department of Transportation Standard Specifications – 2010 3-42 SECTION 306

SECTION 306 -- RECLAIMED STABILIZED BASE

Description

1.1 This work shall consist of scarifying, if necessary, and pulverizing the existing pavement together with a base course material. It may require removal and rehandling and the addition of other materials as shown on the plans or as ordered.

Materials

2.1 General.

2.1.1 The material shall consist of the existing pavement blended with the underlying gravel and/or additional stone as required. Reclaimed stabilized base shall have a minimum bitumen content of 1.5 percent and conform to the following gradation:

Sieve Size Percent Passing By Weight 3 in (75 mm) 100 1-1/2 in (37.5 mm) 80 - 100 3/4 in (19.0 mm) 55 - 90 No. 4 (4.75 mm) 40 - 70

2.1.2 Additional stone as required to meet the above gradation shall meet the requirements of 304.2.1.1 with a maximum size of (1 ½ in) 37.5 mm 2.1.3 Additional asphalt shall meet the requirements of 702, as specified. Construction Requirements 3.1 The existing pavement shall be pulverized together with the underlying base course material and/or additional stone material if required. The pulverizing operation shall blend the existing pavement and base course into a homogeneous mass, using the bitumen contained in the pavement as a stabilizer. The quantity of material mixed with the existing pavement shall be adjusted as necessary to meet the material specification of 2.1.1. 3.2 The reclaimed stabilized base shall be processed, using approved reclaimers. Equipment such as a milling machine or a rock crushing plant will not be permitted. Reclaiming equipment shall be equipped with a gauge to show depth of material being processed. 3.3 Prior to compaction water shall be applied, for the purpose of dust control and to ensure proper compaction. Water may be added during fine grading to improve workability. Additional water shall be applied prior to compaction and may require mixing to blend with reclaimed material to ensure adequate compaction. 3.4 Compaction shall be accomplished by successive passes of a vibratory sheep's foot or pad foot roller of at least 50,000 lb (222 kN) of dynamic force. Final rolling shall be accomplished by a smooth steel wheel vibratory roller of at least 27,000 lb (120 kN) of dynamic force. Density testing shall conform to 304.3.8. 3.5 Gradation shall be determined on the total sample prior to extraction by AASHTO T 27. Bitumen content shall be determined on that portion of the sample which passes a 3/4 in. (19 mm) sieve by AASHTO T 164. The Contractor shall make provisions for an appropriate testing facility for Department personnel to perform the test, AASHTO T 164, as needed. 3.6 Prior to placing the processed material, the roadbed shall be shaped to the specified crown and grade. If the existing roadbed is disturbed, it shall be compacted in accordance with 304.3.6. 3.7 Excess material, unless specified otherwise, shall become the property of the Contractor. 3.8 Care shall be exercised to save all pavement for reclaiming if trenches are constructed prior to processing. 3.9 If the reclaimed stabilized base is not sufficient to complete the project, additional crushed gravel shall be used to make up the deficiency. 3.10 Reclaimed stabilized base specified to be removed and rehandled may be processed in the roadway or off site. The reclaimed stabilized base shall be returned to the highway and placed on the prepared roadbed to the depths specified.

New Hampshire Department of Transportation Standard Specifications – 2010 3-43 SECTION 306

3.11 Additional asphalt may be required to obtain the minimum 1.5 percent bitumen content. 3.11.1 The asphalt shall be applied by a liquid distributor or other approved method, at a rate specified by the Engineer. The asphalt shall be blended with the reclaimed stabilized base using approved mixing equipment. 3.11.2 Asphalt shall not be applied when rain is threatening, during rain storms, or when the air temperature is below 50 F (10 C). 3.11.3 Prior to the addition of asphalt, the moisture content of the reclaimed stabilized base shall be adjusted by aerating or adding water if required. 3.12 If additional stone is used it shall be blended with the reclaimed material using an approved reclaimer. Method of Measurement

4.1 Reclaimed stabilized base, of the depth specified will not be measured, but shall be the square yard (square meter) final pay quantity for material within the limits shown on the plans.

4.2 Additional stone will be measured by the ton (metric ton) in accordance with 109.01.

4.3 Asphalt will be measured by the ton or pound (metric ton or kilogram) in accordance with 109.01.

Basis of Payment

5.1 Reclaimed stabilized base, of the depth specified is a final pay quantity item and will be paid for at the Contract unit price per square yard (square meter), complete in place in accordance with 109.11.

5.1.1 Removal and rehandling or removal of excess material shall be subsidiary to reclaimed stabilized base. 5.2 The accepted quantity of stone will be paid for at the Contract unit price per ton (metric ton), complete in place.

5.3 The accepted quantities of asphalt will be paid for at the Contract unit price per ton or pound (metric ton or kilogram), complete in place.

Pay items and units (English): 306.106 Reclaimed Stabilized Base Processed in Place, 6 in Deep (F) Square Yard 306.108 Reclaimed Stabilized Base Processed in Place, 8 in Deep (F) Square Yard 306.110 Reclaimed Stabilized Base Processed in Place, 10 in Deep (F) Square Yard 306.112 Reclaimed Stabilized Base Processed in Place, 12 in Deep (F) Square Yard 306.206 Reclaimed Stabilized Base Removed and Rehandled, 6 in Deep (F) Square Yard 306.208 Reclaimed Stabilized Base Removed and Rehandled, 8 in Deep (F) Square Yard 306.210 Reclaimed Stabilized Base Removed and Rehandled, 10 in Deep (F) Square Yard 306.212 Reclaimed Stabilized Base Removed and Rehandled, 12 in Deep (F) Square Yard 306.31 Asphalt For Reclaimed Stabilized Base Pound 306.32 Asphalt For Reclaimed Stabilized Base Ton 306.36 Stone for Reclaimed Stabilized Base Ton Pay items and units (Metric): 306.115 Reclaimed Stabilized Base Processed in Place, 150 mm Deep (F) Square Meter 306.120 Reclaimed Stabilized Base Processed in Place, 200 mm Deep (F) Square Meter 306.125 Reclaimed Stabilized Base Processed in Place, 250 mm Deep (F) Square Meter 306.215 Reclaimed Stabilized Base Removed and Rehandled, 150 mm Deep (F) Square Meter 306.220 Reclaimed Stabilized Base Removed and Rehandled, 200 mm Deep (F) Square Meter 306.225 Reclaimed Stabilized Base Removed and Rehandled, 250 mm Deep (F) Square Meter 306.31 Asphalt For Reclaimed Stabilized Base Kilogram 306.32 Asphalt For Reclaimed Stabilized Base Metric Ton 306.36 Stone for Reclaimed Stabilized Base Ton

New Hampshire Department of Transportation Standard Specifications – 2010 3-44